I knew a WW2 vet who often heard entities up on the roof of his apartment, trying to get him ... and sometimes phoned the police to report it. He stuffed rags into every opening he could find ... including the bathroom fan, under doors, around windows etc.
One day, after a bad boiler leak-out ... I had to go up to his floor -the top floor- to deal with air vents in the pipes in each apartment ... and knocked on his door. I heard some kind of muffled reply from inside but no response to open his door. I debated for a while and then decided to use my master key to go in and see what was up.
I did ... and found that he was down ... on the floor ... bare naked. It was stifling hot in there because he'd turned the stove burners on full before collapsing. He'd fallen and simply couldn't get up again.
Because he had rags tucked in underneath the door, I barely heard him. He would have died in a day or two if I hadn't found him. When we cleaned up his apt. We found that he had stuffed the bathroom fan full of rags and then later ... forgot, and turned it on. Because the heat couldn't escape from the fan motor, it caught on fire and melted the plastic cover ... which then fell on the floor and burned a big hole into the linoleum. We had to replace the lino in there.
These hallucinations can be pretty dangerous but I understand that they're pretty real too ... and possibly unavoidable.
Personally, I say to myself -about hallucinations and if I can recognize them as such...
If they have no material substance, they have no way of hurting anyone ... so fear them not.